becomes Highland Avenue and continues to rise and fall, widen and narrow, through the riverside community. US 9 passes in close proximity to Sing Sing correctional facility before heading towards Croton. Croton Expressway Just after Ossining, NY 9A returns and merges with US 9 for approximately 1,500 feet (457 m) as it crosses the mouth of the Croton River and becomes the Croton Expressway. The only section built of the canceled I-487, the highway is generally built to Interstate standards. NY 9A leaves the freeway and returns to two lanes, following the parent route's old course, at the second exit in Croton-on-Hudson, where NY 129 reaches its western end. US 9 passes the Indian Point Energy Center, a nuclear power-plant that supplies power to Westchester County and New York City. The facility is visible from the majority of the northern half of the expressway. The expressway veers inland for much of its route, preferring to follow the railroad tracks (the new Cortlandt station is visible to the west at one point), rather than the river past the promontory at Buchanan. NY 9A, as a surface street, ends at its parent at the Welcher Street exit. It continues on a reconstructed, widened section through Peekskill. Despite recent upgrades to freeway standards, the northern end of the highway still maintains a lower speed limit. from the freeway's northern terminus, US 202 and US 6 join the freeway. NY 35 reaches its western terminus at that same junction. The four-lane divided highway's northern terminus is at a stoplight at a three-way intersection with the Bear Mountain State Parkway. The parkway continues straight from this intersection while US 6/9/202 turns left and crosses Annsville Creek. Peekskill to Poughkeepsie north of that junction, the routes enter the Annsville traffic circle. While 6 and 202 remain concurrent and exit the circle on its west side, continuing up the river towards the Bear Mountain Bridge, US 9 exits the roundabout on the northeast side. It continues due north as two-lane Albany Post Road. Running inland and mostly free of development behind the Hudson Highlands, it enters Putnam County. NY 403 reaches its eastern terminus at the same intersection where the Appalachian Trail crosses the road. The gas station here has, when in service, long been a favorite stop for thru-hikers. A few miles further to the north, at the Indian Brook Road intersection, the highway passes through